SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0433633734b7d66fc94964d576b2da4f0f9a5af1a73c5dd37573081785594b9a' 
  AND token = 'RCn4fufUPEXk4xhTAPiQyEWffIxCWhFSCiJ3OxQ2yPM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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