SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c04f5935296f50b68af137a0e2cf1b621ee213c2d56b0bcc291e81e5fdc3cd9' 
  AND token = 'KsYqV+ey8MYbspnZXvp4CZRirlpKIP/gBXZmcMOqNZw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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