SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6eda1c2d393846b4dd7dbbe1f0472dc770151c4711e0cd7c97b854ad282b305b' 
  AND token = 'Eb4TrOtWqHjYHuyhZjjEgT35CK7gsh4pfAJftcFhD1o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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