SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '68ccdec83efe4dcac4cbbcc3c40c19bd9528a2acf70d67e7691bd38613d99198' 
  AND token = 'nhFMda3JUbK+rLmwThGcpRCiLwHhg2jWNcuvRRkJCbE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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