SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b4999521a9e0c51f3f6323d49ea958b00ac739108355c1ca188c768fe84189e' 
  AND token = '5tqhSwMScE+PhiOuX29lqRl2tpFNrhpxShq7nomWyfM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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