SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e53dd9ea031c5d8d3be175da678364c9954eb9dad5214a369b3ad48fcc215f22' 
  AND token = 'YViy7PVNE2P4HMISD8K/KfZlzPa6dSATzV/vD7jd28c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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