SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f9d164bd7f3f5a203a218b27b7654081505f4d2ba91d1760ff4c0de67c62a8cc' 
  AND token = 'MRJKLdyPZBvQH2wOQWzfa6X2fRTegEc3mCjg9ipaUOg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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