SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '882c0e37c2f74facb89b1375e316fce3adc593c69124115766c3460d53e23683' 
  AND token = 'II2BxWz9NiVbHtMTwGi+zVYGAlaRkg0UJOc9Frgxfuc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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