SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6ba7fe490bed3e2dfa35378983ac6069c9025c85dd8a0286267754fcd7d4618b' 
  AND token = '6V69aYFfWRTu4DkmGyDXH98vt5aPkVNhWtETKASoSKk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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