SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e86e6c9e25a4d441e4bd30034d5a4a1cbfcd7c4f9b7f227bc3b49e1f793180c7' 
  AND token = 'AV/42TGSGXiBp370fGvCtAcqUJnyUO/0jsV8DBGg/lM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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