SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'bbeb7122aca4184a50529845d49258530b813398908f8409a082aabd8effa2bc' 
  AND token = 'DbTXMbcX2CpIBjwF/E5EAPmgzBul4ycnURIyaXElPKA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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