SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd891297b4af5fae6329afc6c36c1b10f760c6228a8cc4ba4667992d6f82e67c3' 
  AND token = 'DYeFRCgVztpEqgVKAal85zGmmf47+h4Ub8djBWLmJdk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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