SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '88f5f1802276cc6b652179707d85b3e39927da504c3b1e3390561207ca8dd162' 
  AND token = 'eV4Xa0nN8V2oTtS+2Q7XB4EFGvOZ8dGHhHCCGJQZXsg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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