SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '60fc0778b12a47d3d4d800fe22204b4d9f5abdc53883115e5126e822132b8b2c' 
  AND token = 'gKuGJp/hOAh5KY3DU9wlkwGteb81KBA98vHbzcZ9xCU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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