SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '1735eb6909cd02948375f5a20261b519501a7f44ec61b53c84f708f4191e236e' 
  AND token = 'Sm2oEE+ih9Bu9zk5Fzo3Op13YwQOP52YGFn7mnD+j0w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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