SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2c5349106f41d2afef0ad96d1d33e3b943652aba68294c898f7a53025c0a7eb3' 
  AND token = 'lMU/7+/GVqtFa8rcUW+yfLZjWQcXRHLn+Cwk0nbR254=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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