SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cd9725aef50be390272cf475dadede8fcee0a28b1edcc7c2ef6eb710a15f6f94' 
  AND token = 'jBfcy1PYYrvtvk5WxLb20ORtv9mk1Ay7nnPvFFWuCko=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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