SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ff93937d5079f453f6ea1652c09aacb513b72c3d285dda211c4b20c7483c7f7a' 
  AND token = 'z/lNGnliabn4HnC7Wa5FILccVm5yXhInJ0wO2q1p3F8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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