SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fc6766d202180dffa09121a20b58ce70d61f3b8e7e42dc7c08609d7a8e3425c4' 
  AND token = 'eiM30BmWeAM1oxDPzRlrOpMYexWDTIhGWIrMgpNZQhc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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