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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6aee83df93a574e270d37ad36d21ab36332c64632d1dfaa45abe3cd765e7ee2b' 
  AND token = 'cd6a2ZwdfGqMCiZIXuQ67hRHHkaNNU+U/2B+DZ/eV6c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}