SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd2252d61be7739fbd524af97ffe7dd32e05bdab7df4a6f2e95ba075722f97247' 
  AND token = 'OJjNWHWXdhV9DY3Xp4HFaZorOu66kGnIGNjnW3z2104=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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