SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'dbf7d7e31a1cd32df54056b1ea7b33ec5b46c1dfcf651edacf803eddbed591e4' 
  AND token = 'mNRebdCs51yeknwRqlhvJWJGBBuy2DfxWmp9WhoJygY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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