SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bddfdd74d1282ff2c1e49820b805ab8fca18dd7f8f82bd78d2c65e2c34fcf50a' 
  AND token = '3QCtGcfnKO2HkJC0rCRagUpLWg0yI5RBoT815a93oPU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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