SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7a66d13d8b3c138a4a2fe2a673b4adc18913ef79daf1765821245a991620fce1' 
  AND token = 'uugjBBzmlHEs4c+9fXsZzcJlQB+SpQKDvEuqp1EOzEU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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