SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c1f517b2b36533bc7a1ecaa690d48907cd56b1dc2424f7779a160c95946419e0' 
  AND token = 'Pi00cOQEXvxvmH86ikl0nEUBc/2En6JjuKZAH4TfStE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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