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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8948253a6a6f50660647cff70eb8e4c8c5c1ebe0b6f40f8363bba066e6c7a57a' 
  AND token = 'Tn0jp7ZxyFc8jxVCzqb0dJjvLFyUT+Z6cNSvC+arhac=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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