SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'eb17116477a5d226b1b05d1d101a9cd5cdfde349c640f2b0d711342ae05dfbf2' 
  AND token = 'cMoUPy0UFzM6gwHB6N//JzNqyXcuZ+JaGyzuvoufpQI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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