SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2a2e4a4924e5eea36afd061576dd222d5d76d6bd58377e299940d1d05e78d28a' 
  AND token = 'iRAzkg31V0mFMewlhTO+7QEr41ACaCe4B09KytVu0jo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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