SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7c1ae17b22c29d588f45d2b56049f2910bb8d1881ed98512487536cf81022652' 
  AND token = 'zmA/5AZI4vnWOKfUKYmUJ4Szp+aQTd3hmq4x5VfDoMQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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