SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cef27075df1805a43156ce51fb7fa8f5db86a09904997d82e09e1dab28412ad1' 
  AND token = 'g8luj4Pkyv/6r8zOgfT2jpyMnpeyiTskZa/3WVSlhP4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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