SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '1c7b937f67aa7cad0d692f17b3fade011d3ee3f79f44bd92b95f2bcfd8ddb08d' 
  AND token = 'hHemuREzbVpPUjzAtQ3HiGv/xFsvbB/3CBpxCggetqE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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