SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a0059d46527cc9792e6bed12ff199541b7c6c6d0ecfa9894d554b9998c2b63ec' 
  AND token = 'qXquj8shOulaKLgEDzX8U+kJTqaOe4qdJypfr8GBzYE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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