SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6473a91bdaad9eb4df8b90636ef5e87b621417a6f0bef1f772688bdb567553e0' 
  AND token = 'VHNH/ppKwtfCR2j3n7NBFcLrvkkB+554CxY9dzLLgLE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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