SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e540c9f464f503613287dd5c99b087a1a77e50fac38d93599b335b5318f0eec4' 
  AND token = 'BIeC2q2fl5610hpxqJ3pjqUQVXdDhaa1Ug74Bzg2tGI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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