SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '852f74a806c71da16ca1127955d310c2b944882fd214455e860bdaf899a50780' 
  AND token = 'eqOmRe+YTpXYpElu9/JXc5KXIBIiU4olh4+EsibKrqw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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