SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92d470fb69b611dfe4dd36a1fbaa637808d1ddca3edfbafa2af270e79ecc9184' 
  AND token = 'lhNWlOEcgBychOKObUU49swa9CuY7LpLYh2LjlReZEs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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