SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ed811f22258ec4f51f20154fdd9e0a27f8bf445332078c85cdc3d4eb6ed52d8e' 
  AND token = '0V+FtGNsEI7kbQdxBMSU+Ck2QFYnTsoNvVPQ8T7bXMI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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