SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'faa44c10e60bf03f5c3f3909fddf68efbbf6d6fdaff7759a5d561487b85a598c' 
  AND token = 'gKujIvZ38OvJlDf8eXIA799/uuk6gIinj9YGMsZkJgA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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