SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e5900adbc4b1e0919bf4e219cfd7fd6883108fcabf2c13e41b7e570355d2aae7' 
  AND token = 'MZyrrK46dl8vos0XOQx45kD8gpjT5O09qZdT1Yu+fkk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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