SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b6d5ae731ccaaad513c5ca29ea5ebe644450a02b28f8b47e2db63994112d44d8' 
  AND token = 'trNeScVMTfQ09UD0JITxNSHURxcP5aPt3XIN0yzz1Fw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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