SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '19f379fedbe9401dc91c0790529e27b12406742d25192e2d223f2ed832b6f75c' 
  AND token = 'V+UjF42CoHwoFabG6v9I5zgcBh9ld/DKpqdsI6PUezY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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