SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '63cd1886f646fbc78e1807557ca32c2049913131d19843ebe1e7427ecd1f5042' 
  AND token = 'x1QeirVn5vfA+cpFlkBQvW1DX7DYPu2q1nhFl+HA2MI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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