SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '080df9782bee184460bb20988d176746e4b0e1b00513ea7b28d76a274d846378' 
  AND token = 'Ffo89Dsojj3vxMD2wpqWB9OsymMRcpiCuTfnKjl/mj0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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