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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3939e77e29e98de0db92eaeaedfa2da1b68bfd7bdfb2afe74b3bbce5aa0fec8c' 
  AND token = '7cBAuG7UDygAZyo3jMQbNDgmNyA6tzTaYD3ojXV8FLs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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