SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6a6a7a11ba932f772134a70b4f90ff70ee10073a579e3a1d5bdf68d8d3a4f467' 
  AND token = 'qT1IxrZTFqet4MMKp2zlVSfmXsOY/WuYr+CIJGkCgFI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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