SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '05fa550927ee436d884342f7a0b39cd6c794a463420db5de642dabcea26eac39' 
  AND token = 'MW4TQbuxZGX0Qmk4iF0PeKY+Fu3oQiW2jNxR4FQrJbE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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