SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a59a0c9c876f5bf84251a92955991f82e84ee37bcb6381a8c2cc5d6a831f4d67' 
  AND token = 'GyaCz97IqROUsamukUk3IBmHtauY2O2UScGQ/NRt53w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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