SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2217949e589d9b23d80b7a71ed9851b647485132d8a9595eb5e770efcc3823e1' 
  AND token = 'UfoTrepT7JktsZqscMunwT95MBjXtM7PmdVQZbVY8vY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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