SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '28aabaab7924e244b6c73fb620bd6ac856af832b873f8471857b9d2e005591c2' 
  AND token = 'rSIkyAcpltNdhT9wh94a/TDLhwt7Q4B2NM5EV96K+Mg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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