SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f116d4d65292a38a54bb8c3a9c0b7df27d5cdc35a6f534097f9fe11163a41149' 
  AND token = 'iywZHFm6diXjxhBUmvxCrdZOSM2TUSgOwwRS6fWhkUk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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