SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '25727fcd40f51d80f353c1665b20e52f354aa827b474853c6ea8f623ccc3d728' 
  AND token = 'CKYsTZg68osZGno2M6ZCGSBE55SCQ8rckaNpAebSMIc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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