SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6908e257d9aec1bbac00466deef38197c9f261668de362e17f0054f4b8a174a6' 
  AND token = 'J9+FutJNqmUWhOfa6j8MLjTM6fVTQCKMORvGY7Wm8s0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}