SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9408b842cd1d8ba65e8096292b3744c212053649ac79397d19f602ad13784c48' 
  AND token = 'F2BTvJRSx933HBrwoyyH9FymzjUlTyfJV++57eQnJE0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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