SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4645dc78a3928dce09bdd8438a913d13601f211978f9ad3685742c3bc19fcf90' 
  AND token = 'vr9kteRispU9TmHIw0iyBgZRi3hMTzP9BfarWS/Tcc0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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