SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '96fb3c7f449601d5acc05d9afad65e05df20ebeaa2fd9609fcfe18a9062004f6' 
  AND token = 'redyV0dK2zPjaQmvff2h+qrvJa8FSUlXm5HlVQxNbds=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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