SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4fe3523be23b900bf84da559151b2ca4d20b4774bc4969cc1169f696e54ef08c' 
  AND token = 'n/ZteQh350+G4IkKjHIzd7arrR1vjBQeIf1M9gPnsr4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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