SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3928f9ea20d99fe1efb2ac9b66f09544e9674f39a1f6696ac29ef97b570fe19a' 
  AND token = '5CKqGB1OHsmIDdPB60XCbKMr0Jz2/utceX4Uaznr2Cw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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