SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8043ec648c2086dbe70ba28269901fbadf0da9e2b3841fadd9ff494ac5d14751' 
  AND token = 'sWVtNBxKaH8nkJr7DMoDCWoUpL0ycP7fBLHhucKHTbY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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