SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b4ddef4ed030fbd25b0b1c04a8bf9bd70346079bc8e332572ccb85be9e4f657' 
  AND token = 'l/60fZ6x0HifqUoY9HW5GdYAN2kUdEEHKbJFeFnAoQE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}