SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '35426dbda2fceedbe0bf083755a2da74906ffa3487803c0ec49e8a6f9cbd413d' 
  AND token = 'iZFxtc2y4jMY3/oErtHcCMjBjf698TXuN2KV6OUeJt8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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