SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'bf3a310862cb90e21206509ee25fa768a2be68dcc8303a1f827be395e56c838a' 
  AND token = 'HdSItKmw/Qx4OWv9x9ctz+opCykdyWQCT2WO1RtTqmk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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