SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '1331fc1fc871064d5ce0216d7b8f305ecb673e14b27970ddead2faf0ba81f435' 
  AND token = '9cABQuFlsJcqUVJBS0pnyB08DLNPZ4+VuH4zWs2/xHA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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