SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b21cca5e36a64b01a33a8b6d0b05c18777360eafde75542007c510affd30695' 
  AND token = 'aqYOycbvwowX1Fznn8U2DrG8Tr6LEjZ8Mak2OpFC61o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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