SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '75146349fb5a9e28680b863b07bb12cb75ec218fe132c230a5b5ad8c2068df9b' 
  AND token = '//0CMwhJWMYyfiKsKNyMMF4+g1rq/bzaGUST7U2ZACA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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