SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24288f226c74c037a5131bdf814afd807ab425107d1424dfc7dee45c16128a4c' 
  AND token = 'hrLMOOxImV4FEls9rOOTB1QBOZBvIvpxMEalucclSS0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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